This project seeks to implement a computer-based controller for closed circuit anaesthesia delivery and cardiopulmonary monitor. The controller is based upon a sophisticated differential equation model of anaesthetic gas uptake by the human body. It is intended to achieve and maintain desired anaesthetic gas concentration, oxygen concentration and circuit volume. Being adaptive in nature the controller is designed to be impervious to patient parameter variations - both between patients and in one patient over time. An estimation scheme incorporated allows the system to sample gas concentrations only once every two minutes. This paves the way for multiplexed use of expensive equipment like mass spectrometers. The inherent nature of the closed system makes it easy to monitor cardiopulmonary parameters with the addition of oximeters. A series of experiments will be performed on dogs under both normal and abnormal physiological conditions to determine the efficacy of the controller. Short and long sensing lines will be used to determine the feasibility of a multiplexed measuring system. The second stage will consist of testing the monitor against accepted techniques.